1. Field of the Invention
This invention relates generally to an articulating mast that may be transported from one well drilling site to another, and more particularly to a folding mast wherein sections of the mast may be moved from an open, in-use position to a reduced width configuration for storage and transportation and then moved from the reduced width configuration to an open position for use.
2. Description of the Related Art
In oil and gas operations, well drilling rigs are utilized to drill for reserves. Many times, drilling does not result in a productive well. Other times, a producing well will be exhausted. It has been estimated that over two million boreholes have been dug worldwide.
Masts or derricks are well known for use in oil and gas and other drilling operations. A mast or derrick of a drilling rig supports a vertically moving block and tackle in order to raise and lower drill pipes. A mast may extend up to 200 feet and is usually comprised of structural steel framework, which supports a crown assembly. The crown assembly is an arrangement of sheaves at the top of the mast or derrick directly above the well bore. Various drilling structure arrangements are known, although one arrangement includes a pair of sides with a back face joining the sides and an open front face. A mast is typically braced on three sides with an open front face to receive pipe sections.
Once a drilling project has been completed, moving the drilling rig from one location to another is required. In one known arrangement, the entire drilling rig is disassembled piece by piece, then transported to the next location, and then reassembled.
As a technological advance on the complete disassembly and reassembly of the mast, a folding gin pole arrangement was developed, wherein the mast was lowered to the ground and disassembled. Normally, the mast sections are transported by trailer. Disassembly of the sections is normally required due to roadway limits as to height and width. For example, certain highway regulations limit the width of the load to twelve feet.
As a further technological advance on the folding gin pole arrangement wherein the mast had to be disassembled to fit onto trailers, an articulating mast was developed. This articulating mast is described in Assignee's patent, Brittain et al., U.S. Pat. No. 6,594,960. The mast therein had an articulating back face, such that the mast sections could be folded to a width acceptable for roadway requirements. Disassembly of each section required only the removal of six pins prior to folding, and assembly required only the insertion of six pens following unfolding. One drawback to the Brittain et al. articulating mast is that any guide track system, top drive, and/or traveling block used on the mast must be removed from the mast prior to disassembly, and reinstalled after assembly.
Based on the foregoing, it would be desirable to provide a mast that may be divided into sections that may be folded to meet roadway requirements for weight, width, and height. Furthermore, it would be advantageous to provide a mast wherein sections may be folded to a width acceptable for roadway requirements.
It would further be desirable to provide a mast having sections that may be moved between an open, in-use position and a more compact reduced width configuration for storage and transportation. It would further be desirable to provide a mast having sections that may be locked in either an open, in-use position or a reduced width, transport or storage configuration.
It would further be desirable to provide an articulating mast wherein the required disassembly and subsequent reassembly time is reduced.
It would further be desirable to provide an articulating mast wherein a guide track system, top drive, and/or traveling block may remain in place on the mast during disassembly, transport, storage, and reassembly.